Relationship between mid-Cretaceous (upper Albian-Cenomanian) ammonoid facies and lithofacies in the Yezo forearc basin, Hokkaido, Japan
Relationship between mid-Cretaceous (upper Albian-Cenomanian) ammonoid facies and lithofacies in the Yezo forearc basin, Hokkaido, Japan
复制标题
DOI：
10.1016/j.cretres.2003.08.001
复制
发表时间：
2003-12-01
影响因子：
2.1
通讯作者：
Kawabe, F
中科院分区：
文献类型：
--
作者：
Kawabe, F
通过对日本北部野左弧前盆地内陆架、外陆架和斜坡沉积的研究，对中白垩统氨相与岩相的关系提供了新的认识。虽然在某种程度上进行了死后转运。菊石没有被移到它们原来栖息地以外的地方。这一假设是基于外壳表面的条件，普遍缺乏破碎，和沉积结构。在上Albian-Cenomanian演替中，无论岩相如何，Desmoceras都占主导地位，Gaudryceratidae在每个岩相中都是第二大优势群。泽兰蒂岩的丰度在近海减少，其他类群，包括棘角藻科，并不常见，但在近岸和近海相都有出现。外壳纹饰不一定因岩相的不同而不同，而螺轮剖面的形状确实因岩相的不同而不同，反映了周围的环境。光滑、细长的泽兰蒂岩和光滑的丝粒岩的压缩形态在高能量状态下占主导地位，其特征是频繁的丘状交叉分层和内层架的电流波纹痕迹。相反，在低能、近海、泥泞的海底环境中，桥孢菌的压抑形态占主导地位。(C) 2003 Elsevier Ltd.版权所有。
An examination of inner shelf, outer shelf, and slope deposits in the Yezo forearc basin, northern Japan, provides new insights into the relationship between mid-Cretaceous ammonoid facies and lithofacies. Although undergoing post-mortem transport to some degree. the ammonoids were not moved to areas outside of their original habitat. This assumption is based on the condition of the outer shell surface, general absence of fragmentation, and sedimentary structures. Desmoceras predominates in the upper Albian-Cenomanian succession regardless of lithofacies, the family Gaudryceratidae is the second-most dominant group in each lithofacies. the abundance of Zelandites decreases offshore, and other groups, including Acanthoceratidae, are uncommon but occur in both inshore and offshore facies. External shell ornamentation does not necessarily vary according to lithofacies differences, while the shape of the whorl section does vary with lithofacies as a reflection of ambient environments. The smooth, slender Zelandites and the compressed morph of the smooth Desmoceras predominate in high-energy regimes represented by frequent hummocky cross-stratification and current ripple marks of an inner shelf. In contrast, the depressed morph of Desmoceras predominates in low-energy, offshore, muddy sea-floor regimes. (C) 2003 Elsevier Ltd. All rights reserved.